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| author | Tejun Heo <tj@kernel.org> | 2012-03-30 07:03:33 +0200 |
|---|---|---|
| committer | Tejun Heo <tj@kernel.org> | 2012-03-30 07:03:33 +0200 |
| commit | 8f121918f2e49f852de1acdc5255cc1ef440d85b (patch) | |
| tree | 552dbbc407189e45b6941cf117b39681dc1f7e40 | |
| parent | cgroup: update MAINTAINERS entry (diff) | |
| download | linux-8f121918f2e49f852de1acdc5255cc1ef440d85b.tar.xz linux-8f121918f2e49f852de1acdc5255cc1ef440d85b.zip | |
cgroup: cgroup_attach_task() could return -errno after success
61d1d219c4 "cgroup: remove extra calls to find_existing_css_set" made
cgroup_task_migrate() return void. An unfortunate side effect was
that cgroup_attach_task() was depending on that function's return
value to clear its @retval on the success path. On cgroup mounts
without any subsystem with ->can_attach() callback,
cgroup_attach_task() ended up returning @retval without initializing
it on success.
For some reason, gcc failed to warn about it and it didn't cause
cgroup_attach_task() to return non-zero value in many cases, probably
due to difference in register allocation. When the problem
materializes, systemd fails to populate /systemd cgroup mount and
fails to boot.
Fix it by initializing @retval to zero on declaration.
Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: Jiri Kosina <jkosina@suse.cz>
LKML-Reference: <alpine.LNX.2.00.1203282354440.25526@pobox.suse.cz>
Reviewed-by: Mandeep Singh Baines <msb@chromium.org>
Acked-by: Li Zefan <lizefan@huawei.com>
| -rw-r--r-- | kernel/cgroup.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/kernel/cgroup.c b/kernel/cgroup.c index f4ea4b6f3cf1..ed64ccac67c9 100644 --- a/kernel/cgroup.c +++ b/kernel/cgroup.c @@ -1883,7 +1883,7 @@ static void cgroup_task_migrate(struct cgroup *cgrp, struct cgroup *oldcgrp, */ int cgroup_attach_task(struct cgroup *cgrp, struct task_struct *tsk) { - int retval; + int retval = 0; struct cgroup_subsys *ss, *failed_ss = NULL; struct cgroup *oldcgrp; struct cgroupfs_root *root = cgrp->root; |